While the present invention was developed for use in positioning clips in stringers utilized in aircraft structures, and drilling holes in the resulting assembly, it is to be understood that the invention can be utilized in other environments.
Currently, during aircraft stringer assembly, aircraft stringers are loaded onto stringer drilling machines. The stringer drilling machine drills pilot holes equal in number to the number required by the clips that are to be attached to the stringers. Normally, four holes are drilled. The drilled stringers are then loaded onto a tool and positioned. Next, clips are positioned by hand with respect to "hard points" associated with the tool. Using the pilot holes previously drilled in the stringers, attachment holes are drilled through the stringers and the clips. This procedure is time-consuming, costly, and subject to inaccuracies. The procedure is time-consuming and, thus, expensive due to the number of manual steps involved. The inaccuracy disadvantage comes from various sources--inaccurate placement of the clips in the stringers, which is primarily related to the tooling; and the manual drilling of the clip/stringer attachment holes through the pilot holes.
The present invention is directed to overcoming the foregoing and other disadvantages. More specifically, the present invention is directed to providing an end effector suitable for use with a computer-controlled machine tool for automatically positioning clips in stringers and drilling attachment holes in the clip/stringer assembly.